Drilling



Sept. 12, 1961 H. STRATTON 2,999,549

DRILLING Filed Sept. 30, 1957 3 Sheets-Sheet l INVENTOR. HAL JTR/ITTO/VA TTORNE Y6 Sept. 12, 1961 H. STRATTON 2,999,549

DRILLING Filed Sept. 50, 1957 s Sheets-Sheet 2 IOJ INVENTOR.

HAL JTAATTO/V Sept. 12, 1961 H. STRATTON 2,999,549

DRILLING Filed Sept. 50, 1957 3 Sheets-Sheet 3 INVENTOR.

HAL JTRA 77' 04' BY 544M654 A TTORNE'YJ United States Patent 2,999,549DRILLING Hal Stratton, Pasadena, Calill, assignor to Shell Gil Company,Continental Oil Company, both corporations of Delaware, Superior OilCompany, Union Gil Company of California, both corporations ofalifornia, all of Los Angeles, Calif.

Filed Sept. 30, 1957, Ser. No. 687,003 14 Claims. (Cl. 175-5) Thisinvention relates to drilling, and more particularly, to equipment fordrilling wells in underwater formations from a floating vessel.

At the present time, floating drilling vessels or barges are used todrill exploratory wells at oflshore locations. A typical floatingdrilling barge uses a rotary drilling rig, which employs a string ofdrill pipes and drill collars extending from the floating vessel down tothe underwater formation. The drilling string is turned by a rotarytable through which extends an elongated kelly joint of square crosssection. The lower end of the kelly joint is connected to the upper endof the uppermost drill pipe, and the drilling string is lengthened orshortened by temporarily uncoupling the kelly joint and adding orremoving a section of drill pipe. The drilling string is raised andlowered on a traveling block.

In conventional rotary drilling at onshore locations, rat and mouseholes are provided at the rig for the temporary storage of drill pipe orthe kelly joint. A typical rat or mouse hole includes an uprightscabbard closed at its bottom and set in a hole drilled at the wellsite. The scabbard is usually of sufficient length to accommodate onejoint or section of drill pipe. Ordinarily, the term rat hole is used todesignate the storage space for the kelly joint, and the term mouse holeis descriptive of the storage space for a section of drill pipe eitherjust removed from the well or about to be placed into the Well.

It is often desirable to use a traveling block guide with fioatingdrilling rigs to prevent the traveling block from swinging dangerouslywhenthe vessel is pitched or rolled due to wave action. Ordinarily, theguide extends down relatively close to the rotary table, and thereforerequires the location of the upper end of a rat or mouse hole fairlyclose to the rotary table to permit the equipment to be placed in orremoved from the rat or mouse holes. However, permanent installation ofa rat or mouse hole closely adjacent the rotary table takes up valuableworking space and hampers other drilling operations.

This invention overcomes the above difliculty by providing a movablescabbard for a rat or mouse hole which is provided with means for movingits upper end toward and away from the rotary table. Thus, the upper endof the scabbard can be moved toward the rotary table to facilitateequipment being stored in or removed from the scabbard, and can be movedaway from the rotary table when not in use.

In the preferred form, the invention contemplates apparatus for drillinga hole in a formation underlying a body of water which includes afloating vessel and means for anchoring the vessel over the formation. Arotary drilling rig is mounted on the vessel over the water, and aderrick floor is disposed over the water. A rotary table is mounted onthe derrick floor and an outwardly extending track is mounted on thevessel with one end of the track nearer the rotary table than the other.A carriage is adapted to move on the track and an elongated anddownwardly extending Scabbard is connected to the carriage. Means areprovided for moving the carriage on the track to carry the Scabbardtoward and away from the rotary table.

Preferably, the invention also includes a guide for limiting lateralmovement of the traveling block used to raise and lower drillingequipment, and the Scabbard is connected to the carriage by a horizontalpivot so the lower end of the scabbard can remain in a relatively fixedposition as the upper end is moved with the carriage. Also in thepreferred form, the lower end of the Scabbard is open and extends belowthe bottom of the vessel. Thus, the length of equipment stored in thescabbard is not limited by the length of the Scabbard as withconventional arrangements. This latter feature is of particular value inhandling drill collars when making trips in or out of the well. Drillcollars are usually so heavy that they must be uncoupled at relativelyshort intervals to prevent possible damage to them due to bending. Withthe open-bottom scabbard of this invention, substantial lengths of drillcollars can easily be stored in. the scabbard without requiringuncoupling, resulting in substantial saving of valuable rig time.

These and other aspects of the invention will be more fully understoodfrom the following detailed description taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a schematic transverse section of a floating vessel embodyingthe presently preferred form of the invention;

FIG. 2 is a view taken on line 22 of FIG. 1, certain non-essentialelements not being shown for simplicity;

FIG. 3 is a view taken on line 3-3 of FIG. 1, certain non-essentialelements not being shown for simplicity;

FIG. 4 is a View taken on line 4-4 of FIG. 1; and

FIG. 5 is a view taken on line 5--5 of FIG. 4 and partially broken away.

Referring to FIG. 1, a floating vessel 10, such as a barge or ship, isanchored by lines 11 in a body of water 1'2 over an underwater formation23 in which a well 24 is being drilled. A draw works 25 and power unit25, which may be of conventional type, are mounted on the deck of thevessel to operate a hoisting cable 27 carried over a crown block 28 atthe upper end of a derrick 29. The traveling end of the hoisting cablecarries a traveling block 30 and a hook 31 which supports a swivel joint32 supplied with drilling fluid through a mud hose 32A connected to apump (not shown). A kelly joint 33 extends downwardly from the swivelthrough a kelly bushing 34 in the center of a rotary table 36 mounted ina derrick floor 37, which extends across the base of the derrick.Preferably, the rotary table is mounted on gimbals in a manner such asthat described in US. Reissue Patent No. 24,083. Power is supplied tothe rotary table through a shaft 40 turned by a rotary table power unit41. As can be seen most clearly from FIGS. 1 and 3, the rotary table issupported directly over a cellar 42 located in the center of the vessel.The cellar opens at its bottom into the water in which the vessel isfloating.

A string of drill pipe 43 is connected to the lower end of the kelly andextends down through the cellar, the Water and into the well. Aplurality of drill collars 46 are attached to the lower end of the drillpipe and a drill bit 47 is connected to the lower end of the drillcollars.

If desired, equipment such as that described in copending applicaitonSerial No. 468,214, filed November 12, 1954 (now US. Patent No.2,808,229) can be used to guide the drill pipe in making trips betweenthe floating vessel and the well.

Referring to FIG. 1, the derrick includes a pair of laterally spaced andvertical traveling block guides 59 which are attached to the derrick attheir upper ends by horizontal sections '52. As shown most clearly inFIG. 2, each guide is an inwardly opening channel section adapted toreceive a separate rotatable wheel 54 mounted on a respective shaft 56between the outer ends of a guide bracket 58 connssted at its water tothe traveling block. Thus, the traveling block is free to movevertically but is prevented from swinging laterally if the vessel shouldpitch or roll due to wave action.

A substantially upright scabbard 60 is disposed in the cellar 42.Preferably, the scabbard is a piece of pipe or casing open at both endsand connected near its upper end by a horizontal pivot 62 to a carriage64 having a pair of inboard wheels 66 and a pair of outboard wheels 68adapted to ride on an outwardly extending track 7t]! attached to theunderside of the derrick floor with the inner end of the track adjacentthe rotary table. The upper end of the scabbard is of increased diameterand projects up through a transverse scabbard-slot 72 in the derrickfloor. The lower end of the Scabbard extends down below the bottom ofthe vessel through a loosely fitting loop 30 attached to the lower edgeof the cellar. The inner end of a piston rodSZ is connected to theoutboard end of the carriage and the outboardend of the piston rod isconnected to a piston 84- disposed in a horizontal cylinder 86 securedby a brace '87 (FIG. to the track 70 and adapted to be supplied air atopposite ends by outboard and inboard airlines 83, 89 respectively,connected to a source of air pressure {not shown).

As shown most clearly in FIG. 4, the carriage includes a pair oflaterally spaced and horizontal longitudinal beams 90 joined at theirrespective ends by cross beams 91. The track is made up of a pair ofhorizontal and laterally spaced I-beams or rails 92 having upperhorizontal flanges 93 welded to the bottom of the derrick platform.Thus, the scabbard is adapted to pivot between the rails in a verticalplane perpendicular to the longitudinal axis of the vessel as thecarriage is moved inwardly and outwardly with respect to the rotarytable. As shown in FIG. 1, the carriage is in the outboard or retractedposition so that the upper end of the scabbard is remote from the rotarytable. A string of drill pipe is disposed in the scabbard and supportedat its upper end by a supporting ring 94 having a downwardly extendingand externally threaded boss 96 screwed into the upper end of the drillpipe as shown most clearly in FIG. 4. The supporting ring is ofsuflicient diameter to rest on the upper end of the scabbard and preventthe drill pipe, kelly joint, etc., from slipping down and out of thebottom of the scabbard.

Although for the sake of simplicity, only one scabbard and carriagearrangement is shown in FIG. 1, FIG. 3 shows how a plurality ofscabbards can be mounted around the rotary table to slide in a directiontransverse to the longitudinal axis of the floating vessel. Thisarrangement is preferred because it leaves a longitudinal space clearfor the handling of casing 160 and drill pipe 102 longitudinallydisposed on the deck of the vessel on either side of the derrick. Ifdesired, the scabbard slots in the derrick floor for the variousscabbards are covered with plates 104, when the scabbards are in theirrespective outboard positions, to provide a continuous working platform.When a scabbard is to be advanced toward the rotary table, itsrespective cover plate is first removed. As shown in FIG. 3, the centerscabbard on the left hand side of the rotary table, which is thescabbard shown in FIGS. 1, 4 and 5, is in the inboard position i.e.,moved in to be adjacent the rotary table.

The operation of the apparatus shown in the accompanying drawings isrelatively simple. Whenever it is desired to store the kelly joint orother equipment such as the drill pipe or drill collars in the scabbardshown in FIGS. 1, 4 and 5, the drill string is secured in the rotarytable by a set of slips (not shown). The cover plate (if used) for thescabbard slot is removed, the drill'string disconnected above the slips,and air is supplied through the outboard line 88 to drive the pistoninwardly and carry the upper end of the scabbard closely adjacent therotary table, the carriage rolling on the track 70. The lower end of thescabbard is held by the loop. 80-near the bottom edge -of the cellar-andis -fr'ee to slide up or down slightly as the scabbard moves inwardly oroutwardly, the scabbard also being free to pivot in a vertical plane (asshown by the dotted line position of the scabbard in FIG. 5).

With the upper end of the scabbard adjacent the rotary table, as shownin FIG. 3, the lower end of the disconnected drill string above therotary table, say the lower end of the kelly joint, is guided manuallyinto the scabhard, and the draw works are actuated to lower thetraveling block so that the kelly joint enters the scab hard. A pair ofslips (not shown) are set to hold the kelly while it is disconnectedfrom the swivel. The ring 94 is screwed into the upper end of the kelly,which is then lowered into the scabbard until the ring rests on theupper end of the scabbard as shown in FIGS. 1 and 4. Air pressure isthen supplied to the cylinder 86 through inboard line 89 to drive thepiston outwardiy and carry the upper end of the scabbard in an outboarddirection until it comes to rest in a substantially vertical positionalong the adjacent wall of the cellar as shown in FIG. 1. The coverplate is then placed over the slot to provide a continuous floor areaaround the rotary table.

Thereafter, the swivel is replaced by elevators adapted to latch on todrill pipe, which may be withdrawn from the well and disconnected asdescribed above, another scabbard being advanced to receive anothersection of the drill string. If the water is sufficiently deep, it ispossible for all of the drill string to be stored in the variousscabbards located around the rotary table. However, in usual practicethe kelly joint isstored in one scabbard, the drill pipe removed andstacked on the deck of the drilling vessel, and then the drill collarsare stored in the remaining scabbards. The drill pipe is of lighterconstruction than the drill collars, and therefore can be laid out onthe deck in longer sections without danger of bending.

As pointed out above, the open-bottom, slidahle scabbards permit thestoring of relatively long sections of drill collars, thus avoidinghaving to'disconnect the drill collars at frequent intervals and therebysaving valuable rig time. The location of the lower end of the scabbardbeiow the bottom of the vessel protects the sides of the vessel orcellar from being. accidentally damaged, or even punctured, as equipmentpasses out the lower end of the scabbard. In addition, the lower end isfree to move upv and down so the upper end of the scabbard carried awayfrom the working areas around the rotary table to facilitate handling ofvarious types of special equipment required in underwater drilling.

I claim:

1. Apparatus for drilling a hole in a formation underlying a body ofwater comprising a floating vessel having a cellar opening at its bottominto the water, means for anchoring the vessel over the formation, arotary drilling derrick mounted on the vessel over the cellar, a derrickfloor disposed over the cellar, a rotary table mounted in the derrickfloor, an outwardly extending track mounted on the vessel with one endnearer the rotary table than the other end, a carriage adapted to moveon the track, an elongated and downwardly extending scabbard in thecellar, a pivot connecting the upper portion of the scabbard to thecarriage, and means for moving the carriage to carry the scabbard towardand away from the rotary table.

2. Apparatus according to claim 1 in which the pivot is horizontal andextends in a direction transverse to the direction of the track.-

3. Apparatus according to claim 1 which includes means for restrainingthe lower portion of the scabbard from lateral movement and forpermitting its longitudinal movement.

4- Apparatus for-drilling a hole in a formation underlying a body ofwater comprising a floatingvessel having a cellar-opening at itsbottom-into the water, means for anchoring the vessel over theformation, a rotary drilling derrick mounted on the vessel over thecellar, a derrick floor disposed over the cellar and having a slot, arotary table mounted in the derrick floor, an outwardly extending trackmounted on the vessel with one end nearer the rotary table than theother end, a carriage adapted to move on the track, an elongated anddownwardly extending scabbard disposed in the cellar with its upperportion in the derrick floor slot, means connecting the scabbard to thecarriage, and means for moving the carriage tobcarry the scabbard towardand away from the rotary ta le.

5. Apparatus according to claim 4 which includes a removable cover platefor the slot.

6. Apparatus for drilling a hole in a formation underlying a body ofwater comprising a floating vessel having a cellar opening at its bottominto the Water, means for anchoring the vessel over the formation, arotary drilling derrick mounted on the vessel over the cellar, a derrickfloor disposed over the cellar, a rotary table mounted in the derrickfloor, a track extending transverse to the longitudinal axis of thevessel and mounted on the vessel with one end nearer the rotary tablethan the other end, a carriage adapted to move on the track, anelongated and downwardly extending scabbard in the cellar and connectedto the carriage, and means for moving the carriage to carry the scabbardtoward and away from the rotary table.

7. Apparatus for drilling a hole in a formation underlying a body ofwater comprising a floating vessel having a cellar opening at its bottominto the water, means for anchoring the vessel over the formation, arotary drilling derrick mounted on the vessel over the cellar, a derrickfloor disposed over the cellar, a rotary table mounted in the derrickfloor, a pair of outwardly extending, horizontal and laterally spacedrails mounted on the vessel with one end nearer the rotary table thanthe other end, a carriage having wheels adapted to roll on the rails, anelongated and downwardly extending scabbard in the cellar and connectedto the carriage, and means for mov ing the carriage along the rails tocarry the scabbard toward and away from the rotary table.

8. Apparatus for drilling a hole in a formation underlying a body ofwater comprising a floating vessel, means for anchoring the vessel overthe formation, a rotary drilling derrick mounted on the vessel over thewater, a derrick floor disposed over the water, a rotary table mountedon the derrick floor, a traveling block mounted in the derrick, meansfor moving the traveling block substantially vertically above the rotarytable, a substantially horizontal track mounted on the vessel with oneportion nearer the rotary table than another portion, a carriage adaptedto move on the track toward and away from the rotary table in adirection transverse to that in which the traveling block moves, anelongated and downwardly extending scabbard connected to the carriage,the scabbard having its upper end at a level in the vicinity of therotary table and extending downwardly at least as far as about thebottom of the vessel and means for moving the carriage on the track tocarry the scabbard toward and away from the rotary table.

9. Apparatus according to claim 8 in which the scabbard is open at eachend.

10. Apparatus for drilling a hole in a formation underlying a body ofwater comprising a floating vessel having a cellar opening at its bottominto the water, means for anchoring the vessel over the formation, arotary drilling derrick mounted on the vessel over the water, a derrickfloor disposed over the cellar, a rotary table mounted on the derrickfloor, a traveling block mounted in the derrick, means for moving thetraveling block substantially vertically above the rotary table, asubstantially horizontal track mounted on the vessel with one portionnearer the rotary table than another portion, a carriage adapted to moveon the track toward and away from the rotary table in a directiontransverse to that in which the traveling block moves, an elongated anddownwardly extending scabbard connected to the carriage and disposed inthe cellar, and means for moving the carriage on the track to carry thescabbard toward and :away from the rotary table.

11. Apparatus according to claim 10 in which the lower end of thescabbard is open and projects below the bottom of the vessel.

12. Apparatus for drilling a hole in a formation underlying a body ofwater comprising a floating vessel, means for anchoring the vessel overthe formation, a rotary drilling derrick mounted on the vessel over thewater, a derrick floor disposed over the water, a rotary table mountedon the derrick floor, a traveling block mounted in the derrick, meansfor moving the traveling block substantially vertically above the rotarytable, upright laterally rigid and elongated traveling block guide meansdisposed above the rotary table and adjacent the path traveled by theblock to be immobile with respect to the derrick, and means engaging theguide means and block to permit the vertical movement of the travelingblock and limit all of its lateral movement, a substantially horizontaltrack mounted on the vessel with one portion nearer the rotary tablethan another portion, a carriage adapted to move on the track toward andaway from the rotary table in a direction transverse to that in whichthe traveling block moves, an elongated and downwardly extendingscabbard connected to the carriage, and means for moving the carriage onthe track to carry the scabbard toward and away from the rotary table.

13. Apparatus for drilling a hole in a formation unde lying a body ofwater comprising a floating vessel, means for anchoring the vessel overthe formation, a rotary drilling derrick mounted on the vessel over thewater, a derrick floor disposed over the water, a rotary table mountedon the derrick floor, a traveling block mounted in the derrick, meansfor moving the traveling block along a substantially vertical path abovethe rotary table, upright, laterally rigid and elongated traveling blockguide means disposed adjacent the path traveled by the block to beimmobile with respect to the derrick, and means engaging the guide meansand block to be slidable along the guide and constrain all lateralmovement of the traveling block as the vessel is pitched and rolled bywave action.

14. Apparatus according to claim 13 in which the guide means includes apair of laterally spaced guide members on opposite sides of the pathtraveled by the 1 block.

References Cited in the file of this patent UNITED STATES PATENTS1,377,575 Greve May 10, 1921 1,447,629 Ramsey Mar. 6, 1923 1,732,887Hansen Oct. 22, 1929 1,829,304 Schroeder Oct. 27, 1931 2,314,323Alexander et a1. Mar. 23, 1943 2,531,930 Woolslayer et a1. Nov. 28, 19502,606,003 McNeill Aug. 5, 1952 2,643,005 Jarnett June 23, 1953 2,885,096Jarnett May 5, 1959

